1. Field of Invention
The present invention relates generally to folding knives, and more particularly to spring assisted opening knives and the lock mechanisms associated therewith for locking the blade in either a fully open or fully closed position.
2. Description of Prior Art
Folding knives typically comprise a handle having a pair of spaced apart handle members defining a groove therebetween and a blade pivotally movable relative to the handle between fully open and fully closed positions. A locking mechanism is generally included with these folding knives to retain the blade in either its fully open or fully closed position. There are a variety of locking mechanisms that have been employed in the past.
Liner locks employ a leaf spring that is attached at one end to the inner surface of one of the handle members and cantilevers therefrom. When the blade is in either its fully open or fully closed position, the leaf spring is biased into engaged relation with the edge of the tang that prevents its pivotal movement. To disengage the liner lock, the spring is manually moved out of engagement with the blade and the blade is manually pivotally moved such that the spring contacts the side of the blade, but does not prevent its pivotal movement to its terminal position. Once the blade reaches its terminal position, the spring is biased into engaged relation with the edge of the blade preventing further movement.
Liner locks are effective at preventing movement of the blade, but are difficult to manipulate. In addition, where the opening of the blade may be assisted by a spring, such as is the case with a switch blade, the operator's fingers would get in the way of the blade's movement, thus creating a significant injury risk. Accordingly, liner locks are not advisable for folding knives utilizing a spring for assisted opening and/or closing of the blade.
Another typical type of blade lock is a spring biased plunger that engages the tang of the blade and prevents it from moving until manually disengaged. The plunger is biased into engaged relation with the tang and requires manual depression by the operator to take it out of engagement. Once the plunger is manually depressed, the blade is free to pivotally move between it terminal positions. Once in its terminal open or closed position, the plunger can be released and it will reengage the tang to prevent further movement of the blade.
The plunger type of lock is useful in spring assisted opening knives because it does not require placement of the operator's fingers in the line of blade travel. The drawback of the plunger style lock is that it can accidentally be depressed, thereby unexpectedly opening the blade. For instance, if the knife is placed in the operator's pocket, it is possible that the plunger will be depressed by the operator leaning against an object, reaching into his or her pocket, or by some other object in the operator's pocket. The unexpected opening of the blade presents an undesirable injury risk.
3. Objects and Advantages
It is therefore a principal object and advantage of the present invention to provide a blade lock for a folding knife that prevents a low possibility of inadvertent blade opening.
It is another object and advantage of the present invention to provide a blade lock for a folding knife that permits the lock to be disengaged without placing the operator's fingers in the line of blade travel.
It is a further object and advantage of the present invention to provide a blade lock for a folding knife that can be incorporated into folding knives without significantly altering their dimensions.
Other objects and advantages of the present invention will in part be obvious, and in part appear hereinafter.